Papers by Keyword: Connective Tissue

Abstract: An investigation has been conducted on burn ligaments, addressing the specific conditions in burn arising from dehydration and heating, and how these affect the structure-property relationship of collagen for reinforcing the tissue. Collagen fibres were isolated from a sheep’s anterior cruciate ligament, i.e. our model for this study, and divided into six groups. The first group was designated as control; the second (D) group was dehydrated without exposure to elevated temperature. The remaining (DH) groups were dehydrated followed by heating at 120oC for 30 minutes, 2, 4 and 24 hours, respectively. Tensile test to rupture was carried out to derive the fibre modulus of elasticity (E), maximum stress (σ), strain at maximum stress (ε) and strain energy density to maximum stress (u). Electron micrographs of the ruptured ends reveal a mixed mode of fibril pull-out and rupture: fibril pull-out dominates in the control group but fibril rupture dominates increasingly in the other groups, i.e. with increasing exposure time to elevated temperature. Apart from ε, there is significant increase in E, σ and u in the D and DH groups with respect to the control group but there is no evidence of variation among the D and DH groups. The results of this study implicate (1) the removal of water in the hydrated proteoglycan-rich matrix, leading to shrinkages at micrometer length-scale during dehydration, and (2) the alteration of the collagen organisation arising from the underlying changes in the crystallinity and denaturation during heating, on the mechanical properties of burn collagen fibres.

Abstract: Carbon nanotubes (CNTs) are composed of two-dimensional hexagonal graphite sheets rolled up to form into a seamless hollow tube or cylinder of diameters ranging from 0.7 to 100 nm and length of several micrometres up to several millimetres [1, 2]. CNTs can be synthesised in two configurations, as single-walled nanotubes (SWCNTs) and multi-walled nanotubes (MWCNTs). Whereas SWCNTs are made of one tubular structure, MWCNTs consist of concentrically arranged carbon tubes with a typical spacing of ≈ 0.34 nm between the different layers. Owing to their remarkable structural characteristics (light weight, high aspect ratio, high specific surface area), as well as attractive mechanical (high stiffness and strength), electrical (high conductivity) and chemical (versatile surface chemistry, easily to functionalise) properties [2], there is increasing interest in biomedical applications of CNTs.

Abstract: A part of the titanium dental implant surface, which will meet connective tissue after being inserted in mandibular bone, was coated with calcium phosphate by ion beam assisted deposition (IBAD). Twenty-four implants of coated and uncoated group were randomly placed in mandibles after 3 months of premolars extraction in beagle dogs. All the implants were firmly anchored in the bone and had no clinical signs of peri-implant inflammation after 3-month insertion. The probing depth in calcium phosphate coated group is 1.9±0.2 mm, less than in control group (2.1±0.2 mm) (p<0.05). Most of the probing sites tended to bleed upon probing in two groups. It might indicate that the calcium phosphate coating has the potential to promote soft tissue integration.